More than 25% of the population in industrialised countries suffer from IgE-mediated allergies. Allergic patients are characterized by the increased production of IgE antibodies against per se harmless antigens (i.e., allergens). The immediate symptoms of Type I allergy (allergic rhinoconjunctivitis, asthma, dermatitis, anaphylactic shock) are caused by allergen-induced cross-linking of mast cell-bound IgE antibodies and the release of biologically active mediators (e.g., histamine, leukotriens).
House-dust mites (HDMs) represent one of the most important allergen sources worldwide. Almost 10% of the population and more than 50% of allergic patients are sensitized to mite allergens. The HDM Dermatophagoides pteronyssinus (Der p) is prevalent in Central Europe. The allergens of Der p comprise more than 30 proteins or glycoproteins of which twenty-one allergens have been characterized so far. Group 1 and 2 allergens (Der p 1 and Der p 2) represent the most important allergens from HDM, which are recognized by more than 80% of Der p allergic patients, but also other HDM allergens (e.g., Der p 5 and Der p 7) were shown to represent important Der p allergens despite a considerably lower IgE-binding frequency.
In Weghofer M. et al. (Clin Exp Allergy 35 (2005): 1384-1391) it was shown that recombinant dust mite allergens are able to inhibit IgE reactivity and hence may be used for diagnostic tests and therapy of Der p allergy.
In Pittner G. et al. (Clin Exp Allergy 34 (2004): 597-603) diagnostic test methods involving the major dust mite allergens Der p 1 and Der p 2 and highly cross-reactive dust mite allergens (for instance Der p 10) to be used for selection of patients for immunotherapy with Der p extracts were described.
In Vrtala S. et al. (Methods 32 (2004): 313-320) strategies for the production and evaluation of allergen derivatives exhibiting a reduced allergenic activity (e.g. hypo-energenic molecules) and suitable for vaccination are disclosed.
The EP 1 612 219 A1 deals with allergens derived from house-dust mites (Der p).
Crude HDM extracts, which are currently used for diagnosis and therapy of HDM allergic patients, are only standardized for Der p 1 and Der p 2, whereas other important allergens are only present in small amounts in HDM extracts.